This invention relates to enclosures for containers, and more particularly to closures which indicate an initial opening of the container.
Manufacturers of consumer goods and purchasers of those goods are concerned with ensuring that products available in the marketplace are not tampered with prior to being opened and used by the ultimate consumer of the goods. For this reason, it is conventional to provide consumer goods in containers having tamper evident closures. Such tamper evident closures are well known in the art, including closures for containers having external screw threads near the opening of the container, such as bottles and jars. In general, such closures have a cap and a tamper evident band which is frangibly connected to the cap. When the closure is initially removed from a container, the frangible connection breaks to separate the tamper evident band from the cap to indicate that the container has been opened. The cap typically includes a threaded portion having interior screw threads, or thread segments, which mate with the screw threads of the container to permit the closure to be screwed onto the container and thereby seal the container. The tamper evident band generally includes one or more ribs which protrude inwardly of the band to engage a retaining flange on the container which is generally positioned beneath the screw threads of the container.
One drawback of prior tamper evident closures is that it is often difficult to install the closure on a container for initial closure of the container without damaging the frangible connections between the cap portion and the tamper evident band. This problem is exacerbated in light of the need to initially install the closures on the containers in a relatively high-speed production line, where the high-speed installation of caps increases the possibility of breaking the frangible connections. One solution to this problem has been to provide a recently molded tamper evident band which has not set and is pliable enough to be installed to a container by permitting stretching of the tamper evident band over the retaining flange of the container without breaking the frangible connections. However, the timing for installing such a closure is critical and often problematic in a mass-production process.
Thus, a need exists for a tamper evident closure which may be easily and quickly installed onto a container without rupturing the frangible connections between the cap portion and the tamper evident band of the closure, while providing a reliable indication of an initial opening of the container.
The present invention provides a tamper evident closure which may be initially installed onto a container without damaging the tamper evident feature, yet provides a reliable indication of a first opening of the container. The closure includes at least one expansion segment on a tamper evident band of the closure which permits the band to be initially installed over a retaining flange on a container without breaking frangible connections between the band and a cap of the closure. The expansion segment permits closures to be quickly installed on containers and are therefore suitable for use in typical production lines.
In an exemplary embodiment, a closure of the present invention includes a cap portion and a tamper evident band portion connected by a series of frangible bridges. The cap portion of the closure includes interior threads which permit the closure to be screwed onto a container having corresponding screw threads on a neck of the container. The tamper evident band is made up of several segments formed together into a unitary piece. The band includes container engaging segments which mate with a retaining flange on a container, and expansion segments which stretch during an initial installation of the closure on the container to permit the closure to be installed without breaking the frangible bridges.
The container engaging segments have raised ribs which are configured to engage the retaining flange of the container. In an exemplary embodiment, the ribs are generally triangular in shape, with a flat surface to engage the retaining flange and a sloped surface which facilitates installation of the band over the retaining flange. The raised ribs extend continuously along the lengths of the container engaging segments. In this embodiment, each container engaging segment has two raised ribs. In another exemplary embodiment, the container engaging segments have a single raised rib.
The expansion segments are positioned between the container engaging segments and do not have raised ribs for engaging the retaining flange of the container. In an exemplary embodiment, the container engaging segments define a peripheral boundary and the expansion segments extend arcuately from the peripheral boundary to create discontinuities in the tamper evident band. Advantageously the container engaging segments and the expansion segments are formed integrally and no subsequent operations are required to create the expansion segment, such as forming slits in the band.
In another aspect of the invention, a tamper evident container system includes a container and a tamper evident closure. The container has an opening and screw threads near the opening for receiving the closure. The closure comprises a cap, with screw threads which mate with the screw threads on the container, and a tamper evident band made up of container engaging segments and expansion segments. The expansion segments permit the closure to be initially installed to the container without damaging the tamper evident features of the closure.
In yet another aspect of the invention, a method for installing a tamper evident closure on a container includes the steps of positioning the closure on an opening of the container and turning the closure to screw the closure onto the container and expand expansion segments on a tamper evident band of the closure, whereby the closure is secured on the container without breaking frangible connections on the band.
These and other features, advantages and objectives of the invention will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings.